A phase 1 study of linifanib in combination with carboplatin/paclitaxel as first-line treatment of Japanese patients with advanced or metastatic non-small cell lung cancer (NSCLC)

Introduction Linifanib is a potent, orally active, and selective inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptor kinase activities with clinical efficacy in non-small cell lung cancer (NSCLC). This phase 1 dose-escalation study evaluated the pharmacokinetics, safety, and efficacy of linifanib in combination with carboplatin/paclitaxel in Japanese patients with advanced NSCLC. Methods Carboplatin (AUC = 6 mg/mL/min) and paclitaxel (200 mg/m 2 ) were administered on day 1 of each 21-day cycle up to a maximum of six cycles. Oral linifanib (7.5 mg) was given to six patients once daily throughout all cycles and escalated to 12.5 mg/day in a second cohort of six patients. Results Twelve patients received at least one dose of linifanib. The most common adverse events were hematologic and consistent with expected toxicities with carboplatin/paclitaxel. With 12.5 mg linifanib, grade 3/4 neutropenia, leukopenia, and thrombocytopenia occurred in 100, 83, and 83 % of patients, respectively. Dose-limiting grade 4 thrombocytopenia occurred in one patient at each dose level. Linifanib pharmacokinetics was similar to that in non-Japanese patients. At 12.5 mg, linifanib C max was 0.32 μg/mL and AUC 24 was 4.29 μg h/mL. Linifanib C max occurred at 2–3 h with both doses and when given alone or in combination with carboplatin/paclitaxel. Exposure to linifanib appeared to be increased by carboplatin/paclitaxel, and exposure to paclitaxel appeared to be increased by linifanib. Partial responses were observed in nine patients. Conclusions Linifanib added to carboplatin/paclitaxel is well tolerated in Japanese patients with advanced/metastatic NSCLC. The recommended dose of linifanib with carboplatin/paclitaxel is 12.5 mg, same as for US patients.